An organic EL device is a planar luminescent material which can emit light of high intensity at a low voltage and can provide various emission colors depending on a type of organic compound contained therein, and in recent years, has attracted attention as a light source of a light emitting module.
The organic EL device generally has a transparent electrode (anode) made up of ITO, an organic emitting layer laminated on the anode, and a cathode laminated on the organic emitting layer. Part of the anode and part of the cathode are derived outside of the organic emitting layer to form electrode extraction units, and these electrode extraction units are electrically connected to a wiring board which supplies power to the organic EL device. This electrical connection is achieved, for example, by providing a soldering metal multilayer film (metal pad) on the electrode extraction units and connecting the metal pad to a metal land of the wiring board by a conductive metal wire (refer to Japanese Unexamined Patent Application Publication No. 2007-324063, for example). The metal wire is soldered to the metal pad and the metal land.
There is also a known light-emitting device in which the metal wire is joined to the metal pad by ultrasonic wire bonding instead of soldering metal wire connection (refer to Japanese Unexamined Patent Application Publication No. 2011-222449, for example).